Therapeutic benefits can be achieved in some instances by providing an active agent to a specific, localized target tissue, instead of systemically. In this manner, the effect of the agent on the target tissue can be maximized while limiting side effects on other tissues. Therapeutic benefits can also be achieved by providing an active agent to a subject in a manner that provides controlled release of the active agent.
One approach to providing these benefits is to use a matrix which retains an active agent before releasing through processes such as diffusion. Another approach to providing these benefits is to use a degradable matrix which retains an active agent before releasing it as the degradable matrix breaks down. Degradable matrices offer the advantage of being able to control the release rate of active agents that do not readily diffuse through non-degradable coatings. In some case, degradable components can be combined with non-degradable components to form hybrid degradable/non-degradable active agent release matrices.
A lipase is a water-soluble enzyme that catalyzes the hydrolysis of ester bonds in water-insoluble, lipid substrates. Lipases comprise a subclass of the esterases. Lipases perform important roles in the digestion, transport and processing of dietary lipids and are thus present in most living organisms. For example, human pancreatic lipase, which is the main enzyme to break down fats in the human digestive system, converts triglyceride substrates found in ingested oils to monoglycerides and free fatty acids.